information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

Sea ivory (Ramalina siliquosa)

Distribution data supplied by the Ocean Biogeographic Information System (OBIS). To interrogate UK data visit the NBN Atlas.
Only coastal and marine records shown



A shrubby, yellow-grey to greenish grey lichen between 2 -7 cm long. The thallus is composed of erect or slightly pendant lobes, arising from the base, little divided, often scimitar shaped but very variable. Lobes may be glossy, or with granular outgrowths (warts) and wrinkled. The lobes are 2-9 mm wide with white spots towards the tips but not normally blackened at the base. The thallus often bears pale fawn coloured fruiting bodies, usually on short stalks. The thallus is hard and brittle when dry.

Recorded distribution in Britain and Ireland

Widely distributed around the British Isles. Gaps in its recorded distribution are probably due to lack of suitable substrata.

Global distribution



Found on hard siliceous rock in and above the splash zone, and inland in areas subject to maritime influence, such as the tops of sea cliffs.

Depth range


Identifying features

  • Thallus fructicose (shrubby), attached to substratum at single point.
  • Thallus hard and brittle when dry.
  • Thallus erect or slightly pendant and yellow-grey to greenish grey in colour.
  • Lobes, 2-9mm wide, white spotted towards the tips, coarsely tufted with granular outgrowths on surface, and rarely blackened at base.

Additional information

Ramalina siliquosa is eaten by sheep in Shetland and North Wales (Dobson, 2000).

Listed by

- none -

Further information sources

Search on:


  1. CABI Bioscience, 2000. Index Fungorum Database. [On-line], 2002-04-23

  2. Dobson, F.S., 1997. Lichens of Rocky Shores. [Foldout pamphlet]. Shrewsbury: Field Studies Council.

  3. Dobson, F.S., 2000. Lichens: an illustrated guide to the British and Irish species. Slough: The Richmond Publishing Co. Ltd.

  4. Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.


This review can be cited as:

Tyler-Walters, H., 2002. Ramalina siliquosa Sea ivory. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 16-08-2018]. Available from:

Last Updated: 12/07/2002